The present invention relates in general to specialized housing constructions, and in particular to a new and useful housing for a camera and associated optical and electrical equipment, which protects the camera and related equipment from temperature extremes.
U.S. Pat. No. 4,933,543 relates to dark signal compensation for diode arrays. This reference teaches the minimizing of thermal noise by maintaining the internal temperature of a camera and the temperature of a diode array as close to ten degrees centigrade as possible. This is achieved with a refrigeration unit including a heat exchanger which cools the diode array as necessary, depending on variations in the internal temperature surrounding the photodiode array. A thermistor drives the temperature compensation circuit for varying the temperature reading upwardly or downwardly depending upon the minimal temperature drift detected by the thermistor.
U.S. Pat. No. 4,301,998 is directed to a vertical gunning apparatus with a television monitor. This reference teaches employing an air conduit for supplying pressurized air to cool and clean a transparent heatresistant port in a line on the side of the lens of the camera. It further employs cooling water conduits concentric with and jacketing the electrical conduit and a substantial portion of the air conduit.
U.S. Pat. No. 4,767,924 discloses a double wall light source having an exterior housing which surrounds a sealed inner housing. A socket allows for the connection of an optical fiber cable. The air in the intermediate space between the inner housing and the exterior housing is continuously replaced by ambient air using a fan to dissipate heat generated therein.
U.S. Pat. No. 4,695,881 relates to an apparatus for imaging infrared emitting surfaces such as those found in the smelt bed of a Kraft recovery boiler. An enclosure covering a camera head/yolk assembly and cooling air is provided in a channel which passes through an air line to the inside of the housing. The housing surrounds the camera head and yolk assembly, and channels the air to the camera lens.
None of the forgoing references disclose or suggest a double wall camera housing with a thermostatic cooling features or circuit arrangement of the present invention.